Spring mounted brake



May 24, 1949. w 2,471,052

SPRING MOUNTED BRAKE Filed March 50. 1945 INVENTOR. JOHN F. WE.|N

Patented May 24, 1949 UNITED STATES PATENT OFFICE John F. Wein,Indianapolis, Ind., assignor to Radio Corporation ci -America, acorporation of Delaware Application March 30, 1945, Serial No. 585,750

'7 Claims. (Cl. 188-166) This invention relates to a brake and has for ione of its objects the provision of means for successively braking aplurality of moving objects.

Another object is the provision of improved means in a brakingarrangement of the character described for compensating for variationsin placement of the different braking surfaces.

A further object is the provision of a brake capable of givingcontinuous accurate and trouble-free service with a minimum ofvibration-under adverse conditions.

An additional object is to provide improved means for effecting a. speedbra-king of the motion of an object, and after braking for holding theobject motionless with respect to the brake- .so as to provide a stablebraking system with a minimumof chatter.

The invention will be described with reference to its use in. a beverageinspection machine which may, for example, be of the type .described inWeathers Patents No. 2,268,098 and No. 2,323,636. The description inthis connection is, however, merely illustrative and it is not intendedto limit the use of a brake accordingto the invention to any particularapplication.

In the accompanying drawing,

Figure l is a view in elevation of a portion of a beverage inspectionmachine including a brake according to the invention,

Figure 2 is an enlarged View of the brake of of Fig. 2,

The bottles 18 to be inspected are transferred from a moving conveyor tobottle supporting-cups [2 arranged on the perimeter of a rotatingturret, indicated generally at M. In a practical inspection machinethere may be twenty such bottle cups arranged around the turret. cup I2is connected by a spindle It to a pulley 1-8 in contact with a drivenspinner belt. By this means the contents of each bottle are'set inspinning motion before inspection. The belt is then disengaged from'thepulley and the spinning mo- Each bottle tion of the bottle to beinspected is stopped abruptly. At this moment a beam of lighter otherradiant energy is directed through the bottle to an appropriateresponsive device; for example, a bank of photocells mounted on a.camcontrolled oscillating swing arm 22, which may be pivoted at theaxisof the turret. Although the spinning of the bottle has ceased, its fluidcontents continue to rotate within the bottle and any particle which maybe in the fluid cuts the beam of light, causes anabrupt variation in theamount of light passing to thephotocells, and actuates appropriaterejection means through the differential response of the'photocells.

A practical machine of the character described may be installed in abottling plant as part of a continuously moving conveyor system whichbrings bottles to the machine from washing, filI- xingand cappingmachines, and. passes the bottles after inspection to a packing station.Effective and continuous braking is very difiicult to achieve because ofthe high humidity. Moreover, the inspection machine is ordinarilyrequired to inspect upwards of I20 bottles per minute and to detectparticles having a diameter of as little as :two millimeters withoutcausing false rejections in excess .of one-half of one per cent of thebottles inspected.

In order to achieve the required speed of inspection while maintainingdesired sensitivity, the rotational movement of the bottles about theperimeter of the turret-as distinct from their spinning motion abouttheir own axes-is not stopped during inspection. In addition to the'photocells, the swing arm 22 bears alight source and lenses forproducing the inspection :beam and moves in perfect step withthe bottleduring inspection. It then swings back rapidly to inspect the succeedingbottle. To avoid an excessive number of .ialse rejections, it isessential-that the bottle shall be perfectly motionless with respect tothe inspecting light beam. During a period of one-half second the arm 22must swing back,

reduce the spinning motion of the bottle from about 1700 revolutions perminute to 'zero,'and travel with the bottle holding it perfectlymotionless with respect to the light beam during inspection, beforeswinging back again to pick up the next bottle. The portion of theaforementioned period of one-half second allotted to braking'must be asshort as possible, so that the larger particles should not have time tosettle at the bottom of the bottle, and so as to allow adequate time forinspection.

It has hitherto been the practice to brake the spinning motion of thebottle to be inspected by means of a braking device which was forcedinto the sheave or groove 24 of the pulley l8 under each bottle cup l2.Under the conditions mentioned above, the brake wore out very rapidlyand it was difficult to achieve the necessary speed and accuracy ofbraking with a minimum of vibra. tion and rolling.

According to the invention each pulley I8 is provided with a separatebraking surface 26. This may be constituted by a member 28 of brakelining or other suitable friction material secured to the lower face 30of each pulley, as for example by rivets, glue or the like. The member28 may take the form of a disk having a central aperture to receive thelower end 18 of the spindle I6.

The brake itself-as distinct from the separate braking surfaces on thelower face of each spinning pulleyincludes a pair of brake shoes 34 and36 mounted by means of springs on a bracket 44 extending from the swingarm 22. The brake shoes may be of any appropriate material, say, castiron or steel. The twenty spinning pulleys are slightly spaced from eachother in a horizontal plane, and the upper surface of the brake shoes ison a slightly higher level than the braking surface 126. However, theforward edges 54 of each shoe are inclined, as shown at 46, so

that on each return stroke of the swing arm the shoes slip under themember 28 and into confronting relation with the braking surface 26.

A block E8 is mounted on bearings 80 which are held in supports 52located towards the front of the brake and extending upwardly from thebracket M. The block is provided with shafts or pins 55 and 58 which aredisposed at right angles to each other; the block thus constitutes auniversal joint. A vertical spring 38 supports the brake shoe 3 and avertical spring 40 similarly supports the brake shoe 36. Each of thesesprings is located towards the forward end of the shoe which itsupports. The lower ends of the two springs rest on arms 6% of bellcranks 52 pivoted on the shaft 56 at either side thereof. At theirforward ends the bell cranks 62 are pivotally connected by pins 64 tolinks 65, which are in turn pivotally connected by pins 68 to theforward ends of the brake shoes 36 and 36, respectively.

An arm it is pivoted at its lower forward end on the shaft 56 of theuniversal joint. At its upper or rear end, it forms a yoke having a web72 and uprights i ivotally connected by pins 75 to the rear of bothbrake shoes. A third vertical spring 42 rests on the bracket 44 andsupports the web l2. It will thus be seen that each of the forwardsprings 38 and is independently associated with the brake shoes 34 and35, respectively, at their forward ends, while the rear spring 42 isconnected to both of the brake shoes at the back. The combination ofbrake shoes and springs is interconnected by means of the arm '59 of thebell cranks 62 and links 66 at the universal joint 48, and permitsfreedom of movement about both shafts 56 and 58.

It would be quite impractical to construct the inspection machine tosuch precise tolerances that the braking surfaces 26 under each bottlecup would all be in precisely the same plane. Moreover, differentialwearing of the braking surfaces and brake shoes, and of different partsof the same surface, enhance differences in the level of the varioussurfaces. The construction outlined, however, compensates for thesedifferences. On each backward stroke of the swing arm, the brake shoescome into confronting relation with one of the braking surfaces. The twofront springs apply different and independent forces to the frontportion of the shoes with which they are respectively associated, whilethe rear spring 42 applies a common force at the back of the brake. Nomatter what the level Of the brakin surface, the brake shoes immediatelyadjust themselves to the proper height because of the freedom ofmovement permitted by the interconnecting universal joint and springs.

While the main braking force to stop the spinning motion is applied bythe two front springs and the main function of the rear spring is tomaintain the surface 26 in braking engagement with the shoes, it is thecombination of these elements which produces beneficial results. Thebrake of the invention lasts much longer than those of the type usedpreviously and effects a substantial reduction in vibration and,therefore, in false rejections.

Variations from the embodiment described within the scope of theinvention will suggest themselves to those skilled in the art. Forexample, it is permissible to use more than two brake shoes, each withits own spring, and a common spring for all the shoes. More than onespring may be used at the back of the brake, if desired. The brakelinings may be attached to the brake shoes instead of to the pulleys, ordispensed with entirely if sufficient braking friction can otherwise besecured. While the invention has been described in an application inwhich it is used to stop the spinning motion of the pulleys and of thebottles which they support, while permitting the continued movement ofthe bottles around the turret, it will be apparent that the invention isequally applicable to stop translatory as well as spinning motion.

There has thus been described a common brake for a plurality of movableobjects, each provided with a braking surface. The brake consists of aplurality of brake shoes, each having separate spring means urging itinto independent braking engagement with a braking surface, and sprinmeans common to all the shoes for imparting to them all a common brakingforce. The various parts of the brake are interconnected by a universaljoint permitting freedom of movement about at least two axes and therebycompensating for variations in placement of the different brakingsurfaces.

I claim as my invention:

1. A brake for a plurality of movable objects, each provided with abraking surface which may be misaligned with corresponding surfaces ofothers of said objects, said brake comprising a pair of brake shoes, asupport for said shoes, means for moving said support relatively to saidobjects to bring said shoes into confronting relationship with each ofsaid surfaces successively, springs independently associated with eachof said shoes and arranged to urge each of said shoes into brakingengagement with the surface confronting it independently of the other ofsaid shoes, further springs common to and associated with both of saidshoes and arranged to urge both of said shoes into common brakingengagement with said surface, and means including a universal jointinterconnecting said springs whereby to compensate for variations inplacement of said surfaces.

2. A brake according to claim 1 wherein the forward edge of said shoesis inclined.

3. A braking arrangement for a plurality of movable objects comprisingmembers having braking surfaces secured to each of said objects, aplurality of brake shoes, means for bringing said shoes into confrontingrelation with one of said surfaces, spring means for urging each of saidshoes into braking engagement with said surface independently of theother of said shoes, further spring means associated with all of saidshoes for urging all of said shoes into common braking engagement withsaid surface, means connecting said shoes and adapted to permit freedomof movement thereof about at least two axes, and means for repeatingsaid braking action with respect to each of the others of said surfacessuccessively.

4. A brake for a movable object comprising a member secured to saidobject and having a braking surface, a plurality of brake shoes, asupport for said shoes, means for moving said support to bring saidshoes into confronting relation with said surface, spring means forbringing each of said shoes into braking engagement with said surfaceindependently of the other shoes, further spring means for bringing allof said shoes into braking engagement with said surface, and meansconnecting said shoes, said connecting means being mounted to permitfreedom of movement thereof about at least one axis.

5. A beverage inspection machine including a plurality of bottlesupporting cups, pulleys connected to each of said cups to spin thesame, brake linings secured to the face of each pulley a pair of brakeshoes, a swing arm constituting a support for said shoes and arranged tobring said shoes into confronting relation with each of said brakelinings successively, springs independently associated with each of saidshoes, and arranged to urge each of said shoes into braking engagementwith the surface confronting it independently of the other of saidshoes, a further spring common to and associated with both of said shoesand arranged to urge both of said shoes into common braking engagementwith said surface, and means including a universal joint interconnectingsaid springs whereby to compensate for variations in placement of saidsurfaces.

6. A brake for a movable object having a braking surface, said brakecomprising a plurality of brake shoes arranged to confront said surface,means for urging said shoes in substantially the same direction intobraking engagement with said surface, said means comprising spring meansarranged to urge each of said shoes independently and further springmeans arranged to urge all of said shoes into braking engagement withsaid surface, said shoes being mounted to permit freedom of movementthereof about at least one axis located in a plane substantiallyparallel to said surface.

7. A brake for a movable object provided with a braking surface, saidbrake comprising a plurality of brake shoes, a support for said shoes,means for moving said support relatively to said object to bring saidshoes into confronting relationship with said surface, means for urgingsaid shoes in substantially the same direction into braking engagementwith said surface, said means comprising spring means arranged to urgeeach of said shoes independently and further spring means arranged tourge all of said shoes into braking engagement with said surface, saidshoes being mounted to permit freedom of movement thereof about at leastone axis.

JOHN F. WEIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 137,393 Tice Apr. 1, 1873 766,117Rundle July 26, 1904 908,232 Finley Dec. 29, 1908 960,055 Sundh May 31,1910 1,588,039 Monosmith June 8, 1926 1,626,941 Lewis May 3, 19271,699,707 Mitchell Jan. 22, 1929 1,840,250 Prescott Jan. 5, 19322,179,334 Keyes Nov. 7, 1939 2,211,077 Schlums Aug. 13, 1940 2,273,481Bone Feb. 17, 1942 FOREIGN PATENTS Number Country Date 570,939 FranceJan. 23, 1924

